/**
**********************************************************************
* @file     main.c
* @brief    对文件的简要说明
* @details  对文件的详细说明
* @author   jcai
* @date     2022-04-29 17:08:16
* @copyright Copyright &copy; 2022 wy1107412334@163.com All rights reserved
* @version  v0.0.1
*
* \n Email:  wy1107412334@163.com
* \n Blog:   None
* \n Github: https://github.com/wy1107412334
* \n Gitee:  https://gitee.com/git.git1107412334.com
*
**********************************************************************
* @note
* None.
**********************************************************************
* @attention
* None.
**********************************************************************
@verbatim
@endverbatim
**********************************************************************
* @par 历史记录
* 1. v0.0.1: jcai, 2022-04-29 17:08:16
*   - 首次编写
*
*<center>Copyright &copy; 2022 wy1107412334@163.com All rights reserved</center>
**********************************************************************
*/

/* 头文件导入区 --------------------------------------------------- */

#include <SDL/SDL_events.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <SDL/SDL.h>
#include <SDL/SDL_image.h>
#include <SDL/SDL_ttf.h>


// 窗口属性
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
const int SCREEN_BPP = 32;

// 将要使用的表面
SDL_Surface *background = NULL;
SDL_Surface *upMessage = NULL;
SDL_Surface *downMessage = NULL;
SDL_Surface *leftMessage = NULL;
SDL_Surface *rightMessage = NULL;
SDL_Surface *message = NULL;
SDL_Surface *screen = NULL;

// 事件结构体
SDL_Event event;

// 将要用到的字体
TTF_Font *font = NULL;
// 字体的颜色
SDL_Color textColor = {0, 0, 0};

SDL_Surface *load_image(const char *file)
{
    SDL_Surface *loadedImage = NULL;
    SDL_Surface *optimizedImage = NULL;

    // 通过 SDL_imag 模块加载图片
    loadedImage = IMG_Load(file);
    if (!loadedImage)   return NULL;

    optimizedImage = SDL_DisplayFormat(loadedImage);
    SDL_FreeSurface(loadedImage);
    if (optimizedImage)
    {
        // 映射关键色
        uint32_t keycolor = SDL_MapRGB(optimizedImage->format, 0, 0xff, 0xff);
        // 将所有颜色为 RGB(0x00, 0xff, 0xff) 的像素设为透明
        SDL_SetColorKey(optimizedImage, SDL_SRCCOLORKEY, keycolor);
    }

    return optimizedImage;
}

void apply_surface(int x, int y, SDL_Surface *src, SDL_Surface *dst)
{
    SDL_Rect offset;

    offset.x = x;
    offset.y = y;

    SDL_BlitSurface(src, NULL, dst, &offset);
}

int init()
{
    if (SDL_Init(SDL_INIT_EVERYTHING) == -1)
        return -1;

    screen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP,
                              SDL_SWSURFACE);
    if (!screen)    return -2;

    // 初始化 SDL_ttf 库
    if (TTF_Init() == -1)
    {
        SDL_Quit();
        return -3;
    }

    SDL_WM_SetCaption("Press an Arrow Key", NULL);

#if 0
    // 给窗口背景填充白色
    SDL_FillRect(screen, &screen->clip_rect,
                 SDL_MapRGB(screen->format, 0xff, 0xff, 0xff));
#endif

    return 0;
}

int load_files()
{
    // 加载背景图片
    background = load_image("background.png");
    if (!background)    return -1;

    // 打开字体
    font = TTF_OpenFont("lazy.ttf", 72);
    if (!font)
    {
        SDL_FreeSurface(background);
        return -2;
    }

    return 0;
}

void clean_up()
{
    SDL_FreeSurface(background);
    SDL_FreeSurface(upMessage);
    SDL_FreeSurface(downMessage);
    SDL_FreeSurface(leftMessage);
    SDL_FreeSurface(rightMessage);

    // 关闭用过的字体
    TTF_CloseFont(font);
    // 退出SDL_ttf库
    TTF_Quit();

    SDL_Quit();
}





/**
**********************************************************************
* @brief    简要说明
* @details  详细说明
* @param    none
* @param[in]     a: 该参数用于输入
* @param[in,out] b: 该参数用于输入和输出
* @param[out]    c: 该参数用于输出
* @retval  none
* @retval  0 函数成功
* @retval  1 函数失败
* @return  返回0成功；否则失败
* @note    none
*/
int main(int argc, char *argv[])
{
    int quit = 0;

    if (init() != 0)
    {
        fprintf(stderr, "SDL初始化失败\n");
        return EXIT_FAILURE;
    }
    if (load_files() != 0)
    {
        fprintf(stderr, "SDL加载 background.png 失败\n");
        return EXIT_FAILURE;
    }

    // 渲染文本
    upMessage = TTF_RenderText_Solid( font, "Up was pressed.", textColor );
    downMessage = TTF_RenderText_Solid( font, "Down was pressed.", textColor );
    leftMessage = TTF_RenderText_Solid( font, "Left was pressed", textColor );
    rightMessage = TTF_RenderText_Solid( font, "Right was pressed", textColor );
    if (!upMessage || !downMessage || !leftMessage || !rightMessage)
    {
        fprintf(stderr, "渲染文本失败\n");
        return EXIT_FAILURE;
    }

    // 将图片应用到窗口
    apply_surface(0, 0, background, screen);

    while (!quit)
    {
        // 处理SDL的事件
        while (SDL_PollEvent(&event))
        {
            // 如果有按钮按下
            if (event.type == SDL_KEYDOWN)
            {
                // 区分是那个按钮按下了
                switch (event.key.keysym.sym)
                {
                case SDLK_UP: message = upMessage; break;
                case SDLK_DOWN: message = downMessage; break;
                case SDLK_LEFT: message = leftMessage; break;
                case SDLK_RIGHT: message = rightMessage; break;
                default: break;
                }
            }
            // 如果用户点击了窗口右上角的关闭按钮
            else if (event.type == SDL_QUIT)
            {
                quit = 1;
                printf("处理退出事件\n");
            }
        }

        // 如果有消息需要显示
        if (message)
        {
            apply_surface(0, 0, background, screen);

            // 显示消息
            apply_surface((SCREEN_WIDTH - message->w) / 2,
                          (SCREEN_HEIGHT - message->h) / 2,
                          message,
                          screen);
            message = NULL;
        }

        // 更新窗口
        if (SDL_Flip(screen) == -1)
        {
            fprintf(stderr, "SDL更新窗口失败\n");
            break;
        }
    }

    clean_up();

    return 0;
}




/***  Copyright (C) 2022 wy1107412334@163.com All rights reserved ***/
/****************************** END OF FILE *************************/

